Believers in Jesus Christ have a lot of enemies in life. Some are more serious than others, but there is no doubt, we have many enemies. For some it’s a co-worker or a classmate. For others it’s a family member or a former friend. But I want us to ask, who or what is our greatest enemy? Now before you answer that too quickly, you might want to think about it on a deeper level. We are tempted to answer emphatically, “It’s Satan!”, but I’m not convinced he is. No, I believe our greatest enemy is even more deceptive than Satan.

To identify our greatest enemy, let’s turn to Hebrews 4. The main topic here is entering God’s Sabbath rest, or heaven. In the Old Testament, the Promised Land was the rest that the Israelites sought after, and it served as a foreshadowing of the heavenly city to come (Heb.11:13-16). Hebrews 4:11 emphasizes the seriousness of entering God’s rest, saying,

Hebrews 4:11--“Let us therefore strive to enter that rest, so that no one may fall by the same sort of disobedience.”

The word strive is the main verb that drives verses 11-13. It is a word that describes a passionate effort to do something even at the expense of comfort. In this case, we are to “strive to enter” heaven because it is worth every pain and discomfort, for we have been called to bear the painful cross of Christ. We see in verse 11, however, that the Israelites failed to enter God’s rest because of disobedience, and their disobedience remains a temptation for all people even today. In fact, this disobedience is our greatest enemy. So this leads us to ask a few questions:

What was the Israelites disobedience? The Israelites disobeyed with their unbelief. Even so, the core of sin is always prideful and selfish unbelief. Every sin under heaven is a constant cry “I DON’T BELIEVE YOU GOD! ” or else, "I WON'T BELIEVE YOU GOD!" Hebrews 3:19 notes the Israelities disobedience through unbelief:

Hebrews 3:19--"So we see that they were unable to enter because of unbelief.”

What did the Israelites fail to believe? We see the answer to this particularly in Hebrews 4:2:

Hebrews 4:2--“For good news came to us just as to them, but the message they heard did not benefit them, because they were not united by faith with those who listened.”

They failed to believe the good news of God’s word—His promises of protection, provision, and ultimately salvation. Rather than believe God, what did the Israelites do? They listened to their own sinful hearts rather than God. We too have received good news, called the gospel of Jesus Christ. Listen carefully. Believing God’s word is necessary for entering God’s eternal rest, “for whatever does not proceed from faith is sin” (Rom.14:23). That makes unbelief our greatest enemy because it threatens us with hell. And beware of pride at this point, for pride and unbelief go hand-in-hand. We often proudly proclaim that we believe God’s word, that we believe the gospel. But unless a godly lifestyle of repentance and obedience accompanies our belief, there is no real belief. The Bible testifies to this fact again and again:

James 2:26--“You believe that God is one; you do well. Even the demons believe—and shudder!”

James 1:22-24-- “But be doers of the word, and not hearers only, deceiving yourselves. For if anyone is a hearer of the word and not a doer, he is like a man who looks intently at his natural face in a mirror. For he looks at himself and goes away and at once forgets what he was like.”

What is our only defense against our greatest enemy of unbelief? Hebrews 4:12-13 answers this question for us most powerfully:

Hebrews 4:12-13--"For the word of God is living and active, sharper than any two-edged sword, piercing to the division of soul and spirit, of joints and of marrow, and discerning the thoughts and intentions of the heart. And no creature is hidden from his sight, but all are naked and exposed to the eyes of him to whom we must give account."

Our only hope of slaying the great dragon of unbelief is the word of God. Notice the three main characteristics of God's word here that bring us hope.

1. God’s word is living: The verb used for “living” actually begins the sentence, which emphasizes to us that this is one of the most unique characteristics of the Bible. It is not your average book. In fact, there is no other book like it. It is a living book, and as such, it is life-giving. We see a multitude of examples of this throughout Scripture. Here’s just a few:

1 Peter 1:23--“since you have been born again, not of perishable seed but of imperishable, through the living and abiding word of God;”

Deuteronomy 8:3--“And he humbled you and let you hunger and fed you with manna, which you did know, nor did your fathers know, that he might make you know that man does not live by bread alone, but man lives by every word that comes from the mouth of the LORD.”

Ezekiel 37:7-10--“So I prophesied as I was commanded. And as I prophesied, there was a sound, and behold, a rattling, and the bones came together, bone to its bone. And I looked, and behold, there were sinews on them, and flesh had come upon them, and skin had covered them. But there was no breath in them. Then he said to me, ‘Prophesy to the breath; prophesy, son of man, and say to the breath, Thus says the Lord GOD: Come from the four winds, O breath, and breathe on these slain, that they may live.’ So I prophesied as he commanded me, and the breath came into them, and they lived and stood on their feet, an exceedingly great army.”

2. God’s word is powerful: The word for “powerful” is one used to describe God’s word as both effective and active. As such, God accomplishes His will through it. Do you remember what God said through Isaiah?

Isaiah 55:10-11—“For as the rain and the snow come down from heaven and do no return there but water the earth, making it bring forth and sprout, giving seed to the sower and bread to the eater, so shall my word be that goes out from my mouth; it shall not return to me empty, but it shall accomplish that which I purpose, and shall succeed in the thing for which I sent it.”

We must be careful not to get caught up in our own expectations of what we believe the word ought to accomplish. Too often the preacher is blamed (and sometimes perhaps rightfully so), but friend, if the word of God is preached faithfully and truly, God is doing a mighty work that only He fully understands.

For example, I once had someone approach me after a morning sermon complaining about the length of the sermon (though it was really about the length of the service) and how people “had places to be” and “things to do.” I politely responded, that if “people have more important things to do, then they were welcome to excuse themselves.” Interestingly, while this person and a handful of others were murmuring, two people contacted me the next week testifying to the power of God’s word in their lives from that sermon. God’s word is powerfully effective!

3. God’s word is piercing: The Bible is said to be sharper than a double-edged sword. Such a sword is designed for maximum effectiveness. The writer piles up the language here. It’s not just that God’s word is sharper than any two-edged sword but that it is beyond-sharper.

Because of its effective sharpness, God’s word cuts very deeply. It cuts things that would otherwise be inseparable, like soul from spirit, joints from marrow, and thoughts from intentions. The point is this: the word of God penetrates to the deepest part of who we are and judges what is there. Ultimately, God’s word pierces to the depths of the heart discerning whether our thoughts and intentions are believing or unbelieving. And this is exactly what we need because our hearts are “deceitful above all things and desperately sick” (Jer.17:9). Hebrews 3:12-13 says it like this:

Hebrews 3:12-13--“Take care, brothers, lest there be in any of you an evil, unbelieving heart, leading you to fall away from God. But exhort one another every day, as long as it is called ‘today,’ that none of you may be hardened by the deceitfulness of sin.”

As a double-edged sword, God’s word has at least two characteristics:

a. It can be a painful-pleasure: Much like the surgical scalpel that cuts through tissue and muscle in order to get to the cancerous tumor, God’s word can be both bitter and sweet. The cut can be painful, but the cut will result in healing and godly pleasure for God’s people.

b. It can be a controversial-peace: It embitters unbelievers and believers alike because it exposes sin deep in our hearts. Unbelievers that refuse to believe will continue in this bitterness because they refuse to submit to God’s surgery. Believers, however, will be renewed through repentance and belief, or else they do not know Christ (1 Jn.1:8-9).

Though the word can be quite controversial, it always brings peace to God’s people. Listen to what Jesus has taught us, and notice how He alludes to both the controversy and the peace that results from God’s word:

John 16:33--“I have said these things to you, that in me you may have peace. In the world you will have tribulation. But take heart; I have overcome the world.”

Verse 13 then gives the reason that the word of God is so alive, powerful, and piercing, namely God has a full view of every created thing. All things are uncovered to the eyes of God. Literally, the word means naked, which tells us that God is omniscient, knowing all things. Psalm 139 is one of my favorite reminders of this:

Psalm 139:7-8—“Where shall I go from your Spirit? Or where shall I flee from your presence? If I ascend to heaven, you are there! If I make my bed in Sheol, you are there!"

And all people will give an account to this all-seeing God. We will all answer for our sin, and only those who have treasured Jesus more than anything else will find mercy on the Day of Judgment. For Jesus is our high priest, representing His redeemed people before God the Father (Heb.4:14-16). By God's grace, may we hear the word of God, submit to the painful process of cutting out unbelief, and be renewed through repentance of sin and faith in God's promises.